The present invention relates to folding ramps. More particularly, the invention is directed to a folding ramp that provides access between two surfaces of different heights, such as from a truck or dock surface to the ground surface.
In the loading and unloading of trucks, a ramp is often used to span the distance from the truck trailer to the ground surface. Similarly, a ramp is also used to span the distance from a dock surface to the ground surface. These ramps allow, for example, the trailer to be unloaded by providing a walking surface from the trailer down to the ground. The surface of the ramp also allows unloading dollies or hand-trucks to be used in unloading the contents of the trailer.
Some truck trailers are specially equipped to transport a variety of items requiring different storage temperatures. For example, truck trailers known as xe2x80x9cmulti-tempxe2x80x9d trailers may be equipped with non-refrigerated, refrigerated and freezer compartments. Each of these compartments must be equipped with an access area for loading and unloading. This access area is typically provided in the form of a door located on the side of the trailer. In most instances, a ramp is used to span the distance from each of the side doors down to the ground surface. In using a ramp to unload these trailers, it is therefore necessary to move the ramp from one side door to another as the various compartments are unloaded. As is known within the art, trailers may also be provided with an access door at the rear of the trailer for loading and unloading.
Prior art ramps used in this environment suffer from a number of drawbacks. In typical prior art ramps, the ramp is a unitary, rigid structure that has a length sufficient to span the distance from the trailer surface to the ground at an angle that allows the trailer to be unloaded safely and comfortably. These prior art ramps are typically equipped with wheels at one end thereof. The wheels allow the ramp to be maneuvered into position. However, the length of these prior art ramps hinders the maneuverability of the ramps, making the relocation of the ramps from door-to-door a cumbersome task.
Moreover, it is often desirable to store a ramp somewhere within the trailer, so that each trailer is equipped with a loading or unloading ramp. The prior art ramps have an overall length that requires that they be stored so that they are oriented longitudinally within the body of the trailer. Therefore, the prior art ramps are stored on the trailer so that they are accessible and removable from a only the rear of the vehicle. In trailers having side access doors, this requires the ramp to be removed from the rear of the trailer and moved to the side access door corresponding to the compartment being unloaded. As noted above, the overall length of these prior art ramps makes this movement somewhat cumbersome.
Yet another drawback to prior art ramps is associated with their length and unitary construction. In these prior art ramps, the ramp in use is supported only at each end, with one end supported by the trailer and the other end supported by the ground surface. Even when made of strong, lightweight materials some deflection of the ramp occurs in use. Obviously, when more weight is placed on the ramp, more deflection occurs. It is desirable, however, to have as little deflection as possible, so that the ramp provides a sturdy and secure surface over which items may be loaded and unloaded.
A prior art ramp has been made that addresses some of the above problems. This prior art ramp is equipped with a generally centrally disposed hinge. This hinge allows the ramp to be folded, effectively dividing the ramp in half for movement of the ramp from door to door, which allows it to be more easily maneuvered. This prior art ramp is also equipped with a leg structure that is fixedly attached adjacent the hinge. The leg structure has a pair of wheels thereon which allow the ramp to be maneuvered into place, after which it may be unfolded. The leg structure thus adds to the maneuverability of the ramp. The leg structure also decreases the deflection experienced by the ramp by providing an additional support in the mid-section of the ramp. This prior art ramp, however, still suffers from a number of drawbacks. For example, the wheels of this ramp are located at the bottom of the leg structure. These wheels remain in contact with the ground surface, even when the ramp is being used. These round wheels, by nature, do not offer as solid a contact point with the ground surface as may be desired. Moreover, while this ramp can be folded in half, the fixed leg structure makes it more difficult to store on the trailer due to its awkward overall shape.
Therefore, an apparatus is needed that overcomes the above drawbacks and disadvantages existing in the prior art.
It is an object of the present invention to provide a ramp that can be easily stored under a truck trailer in a transverse orientation relative to the trailer and close to side access doors of the trailer.
It is another object of this invention to provide a ramp that can be easily maneuvered from one position to another.
It is a object of the invention to provide a ramp that offers increased stability and decreased deflection when in use.
It is yet another object of the invention to provide a ramp with a pivotal leg support structure that can be deployed for maneuvering and use and that can be retracted for storage.
It is still another object of the invention to provide a ramp with a pivotal leg support structure that has retractable wheels therein that may be deployed for maneuvering and retracted when the ramp is being used to load and unload a trailer.
According to the present invention, the foregoing and other objects are attained by a folding portable ramp that includes a first platform section having a first end and a second end, and a second platform section having a first end and a second end. The first end of the second section is pivotally coupled to the second end of the first platform section, and the second section is adapted to be pivoted relative to the first section. A leg support assembly is coupled to at least one of the first and the second platform sections. The support assembly is adapted to be pivoted between a first position wherein the support assembly is oriented generally parallel to the first and the second sections and a second position wherein the support assembly extends outwardly away from the first or second section.
Additional objects, advantages, and novel features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.